Cultivar Selection is an Effective and Economic Strategy for Managing Charcoal Rot of Strawberry in Florida.

Macrophomina phaseolina, the causal agent of charcoal rot, is a soilborne pathogen that affects strawberry crowns leading to plant wilt and collapse. Disease management involves a combination of physical, cultural, and chemical methods. Field trials were conducted for ten consecutive Florida seasons (2010-11 to 2019-20) to determine the susceptibility of strawberry cultivars to charcoal rot and the effect of cultivar selection on disease, and to estimate the economic impact of cultivar selection on disease management. Six cultivars grown commercially in Florida were chosen and, according to their susceptibility levels, grouped as highly susceptible (HS) ['Strawberry Festival' and 'Treasure'], susceptible (S) ['Florida Radiance' and 'Florida Beauty'], and moderately resistant (MR) [Sensation® 'Florida127' and WinterstarTM'FL05-107']. Following primary analysis of the individual trials, a network meta-analysis was conducted to estimate and compare the final disease incidence and the disease progress rate of each susceptibility group. The economic impact of charcoal rot on strawberry production and gross revenue was estimated based on plant production functions, weekly fruit prices, and disease progress over time with parameters obtained via the meta-analytical models. Disease incidence was reduced by 91.5 and 77.3%, respectively, when MR and S cultivar groups were adopted instead of HS group; and there was a 62.5% disease incidence reduction when MR group was used instead of S group. Significant differences in disease progress rates were also observed when MR and S groups were adopted instead of HS. Therefore, the adoption of more resistant cultivars is an effective strategy when incorporated into a charcoal rot integrated management program and can significantly impact growers' revenue by reducing disease incidence, preventing yield loss and, consequently, minimizing economic losses.